Laboratory measurements of Kβ transition energies of Sulfur ions from F-like to Li-like

Inner-shell transitions are ubiquitous in non-equilibrium collisionally ionized plasmas, such as supernova remnants, and in photoionized plasmas, as found in outflows from active galactic nuclei and X-ray binaries. Despite the importance of these features, only theoretical inner-shell transition energies are available for many ions. We measured the dominant K-shell transitions of Sulfur ions from Li-like to F-like for excited states with n≥3 using the LLNL electron beam ion trap superEBIT and the NASA/GSFC EBIT calorimeter spectrometer (ECS). We identify over 30 lines and blends in the spectra and measure their energies with uncertainties ranging between ~100 meV and ~1 eV. We compare these results to Flexible Atomic Code (FAC) and multi-reference Moeller-Ploesset (MRMP) calculations and find differences between theory and experiment as high as 2 eV. We also compare these results to two widely used atomic databases, AtomDB and CHIANTI, and find discrepancies as high as 7 eV. Further, many transitions are missing from these databases despite being prominent in our data.